The neural crest is a migratory population of cells in vertebrate embryos that is induced at the boundary between the neural plate and non-neural ectoderm. While many studies have focused on the mechanisms underlying neural crest migration and differentiation, its origins from the ectoderm are less well understood. Recent experiments in our lab suggest that a Wnt signal appears to mediate this induction, but its molecular mechanism is not understood. Therefore, candidate genes expressed in the dorsal neural tube will be assessed for their dose and temporal responsiveness to Wnt signaling using a quantitative PCR assay. These putative targets will then be further analyzed for their regulation by B-catenin. To identify additional (and perhaps novel) genes involved in crest induction that are regulated by Wnt signaling, a genomics approach will be employed. To this end, chick homologs to genes identified in my graduate work to be Wnt responsive will be examined for their role in crest induction. In addition, cDNA macroarrays will be hybridized with cDNA isolated from neural plates cultured with Wnt conditioned medium. Thus, the long-term objective is to describe Wnt induction of the neural crest at a molecular level, and, in doing so, garner more knowledge concerning the development of various human craniofacial disorders and neural crest-derived cancers [unreadable] [unreadable]